Student spins a spinner and he chooses a scrabble tile. is this independent or dependent

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Consider the sequence below. 3 , 1 , 1/3 , 1/9 , select the explicit function which defines the sequence.

How is this equation completed? i cannot find any examples in the book.